From 8b849016ba99e3bdfa74ecc0e6d5ac8bafc8c56a Mon Sep 17 00:00:00 2001
From: NerdyPepper <akshayoppiliappan@gmail.com>
Date: Sat, 16 Mar 2019 22:07:02 +0530
Subject: write basic AST structure

---
 src/main.rs | 47 +++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 41 insertions(+), 6 deletions(-)

(limited to 'src')

diff --git a/src/main.rs b/src/main.rs
index c9d02f7..6a97d1c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,12 +1,39 @@
 #[derive(Debug)]
-enum Token {
+pub enum Token {
     Operator(char),
     Num(f64),
-    Paren(char)
+    LParen,
+    RParen
+}
+
+#[derive(Debug)]
+pub struct Node {
+    value: Option<Token>,
+    left: Box<Option<Node>>,
+    right: Box<Option<Node>>
+}
+
+impl Node {
+    fn new() -> Node {
+        Node {
+            value: None,
+            left: Box::new(None),
+            right: Box::new(None)
+        }
+    }
+    fn set_val(&mut self, val: Token) {
+        self.value = Some(val);
+    }
+    fn set_left(&mut self, val: Node) {
+        self.left = Box::new(Some(val));
+    }
+    fn set_right(&mut self, val: Node) {
+        self.right = Box::new(Some(val));
+    }
 }
 
 fn main() {
-    let input = "11(12)";
+    let input = "11 + (1 + 2(3))";
     let input = input.replace(" ", "");
 
     let lexed = lexer(&input);
@@ -23,29 +50,35 @@ fn lexer(input: &str) -> Result<Vec<Token>, String> {
                 num_vec.push(letter);
             },
             '+' | '-' | '/' | '*' | '^' => {
+                // parse num buf
                 let parse_num = num_vec.parse::<f64>().ok();
                 if let Some(x) = parse_num {
                     result.push(Token::Num(x));
                     num_vec.clear();
                 }
-                result.push(Token::Paren(letter));
+                // finish
+                result.push(Token::Operator(letter));
             },
             '('  => {
+                // parse num buf
                 let parse_num = num_vec.parse::<f64>().ok();
                 if let Some(x) = parse_num {
                     result.push(Token::Num(x));
                     result.push(Token::Operator('*'));
                     num_vec.clear();
                 }
-                result.push(Token::Paren(letter));
+                // finish
+                result.push(Token::RParen);
             },
             ')' => {
+                // parse num buf
                 let parse_num = num_vec.parse::<f64>().ok();
                 if let Some(x) = parse_num {
                     result.push(Token::Num(x));
                     num_vec.clear();
                 }
-                result.push(Token::Paren(letter));
+                // finish
+                result.push(Token::LParen);
             }
             _ => {
                 return Err(format!("Unexpected character: {}", letter))
@@ -54,3 +87,5 @@ fn lexer(input: &str) -> Result<Vec<Token>, String> {
     }
     Ok(result)
 }
+
+
-- 
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